2025 Pool Shock Calculator: Free & Easy to Use!

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A pool shock calculator is an invaluable tool that makes it easy to determine the amount of shock to add to your pool based on specific factors such as pool size, current chlorine levels, and the type of shock being used.

Calcium hypochlorite (Cal-Hypo) is one of the most popular and powerful types of pool shock. It is known for its fast-acting properties and effectiveness against algae and bacteria.

It typically contains 65% to 75% available chlorine. Moreover, it is un-stabilized and will not increase the Cyanuric Acid (CYA) levels. However, it tends to increase the Calcium Hardness.

Sodium dichlor is a stabilized chlorine shock that dissolves slowly and is suitable for various pool types, including saltwater pools.

It typically contains about 50% to 60% available chlorine. While it does not increase Calcium Hardness, being stabilized, it will increase the Cyanuric Acid (CYA) levels.

Sodium hypochlorite, commonly known as liquid chlorine, is sometimes used as pool shock. However, as the chlorine content is only 12.5%, it is not a very popular choice as pool shock.

Pool Shock Calculator (Granular or Powder Shocks)

Recommended Cyanuric Acid Free Shock (Cal Hypo) - Powder

Recommended Calcium Free Shock (Di-Chlor)

Pool Shock Calculator (Liquid Chlorine)

To use Liquid Chlorine as Shock you can use the Liquid Chlorine Shock Dose Calculator below to spike up the Free Chlorine to the Target (ppm).

Please input the following:

• Existing Free Chlorine (FC) in ppm
• Target Free Chlorine (FC) in ppm. For effective super-chlorination keep this between 10-20 ppm.
• Pool Volume (in Gallons)
• Available Chlorine Percentage (ACP) - This is 12.5%. You can use a weaker chlorine such as Household Bleach (6%) but you will need to use very high volumes which is not practical.

Clicking the "Calculate" button will give you the Liquid Chlorine Shock Dose (Gal).

Recommended Cyanuric Acid Free Liquid Chlorine Shock

Pros & Cons of Powder vs Liquid Shock

If you are looking for a Cyanuric Acid (CYA) Free shock then the choice usually boils down to Cal-Hypo Granular Shock or Liquid Chlorine Shock.

Here are some of the pros & cons of powder & liquid shock:

Pros of Powder Shock:

• Higher %age of Active Chlorine as compared to liquid shock
• More cost-effective and affordable
• Easy to buy, can be ordered online
• Easy to store as takes up less space
• Can be stored for longer periods of time
• Dichlor does not alter pool pH

Cons of Powder Shock:

• Must be pre-dissolved in water for best dissipation
• Cal Hypo increases pH, total alkalinity and calcium hardness
• Dichlor increases cyanuric acid level in pool

Pros of Liquid Shock:

• Easy to use as can be poured directly into the pool
• Does not leave any residue
• Will not increase calcium hardness or cyanuric acid level

Cons of Liquid Shock:

• More expensive than powder shock 
• Can not buy liquid chlorine online
• Has a short shelf life of just 4 - 6 weeks
• Deteriorates if exposed to heat or sunlight
• Will increase pool pH substantially
• Will increase total dissolved solids in the pool
• Must be careful during application as it is basically concentrated bleach

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Thank you very much for reading the post. I do hope you found it informative and helpful.